This invention relates generally to a coupler assembly for railway cars and the like. More specifically, the present invention relates to an improved yoke for such a coupler assembly. Although the invention will be described with particular reference to a yoke for rotary coupler assemblies in railway cars, it will be recognized that certain features thereof may also be used or adapted to use in other applications.
After the introduction of the rotary coupler assembly, a train comprised of loaded railroad cars of the open top or hopper-type (which may contain coal, ore, etc.) could be emptied without having to uncouple and separate the cars. This was accomplished by rotating each car up to 180.degree. about its longitudinal centerline while it remained connected on both ends to adjacent cars. Such capability speeded up the gravity empyting process. Rotary coupler assemblies typically include a yoke assembly and a coupler unit, along with a follower, a draft gear, and a striker.
Yokes of the known-type include a generally rectangular front portion having a central opening and a pair of opposed straps extending rearwardly from the front portion with a bridge portion connecting the free end portions of the straps. The tremendous growth in the size of railroad cars in the past decade has, however, placed severe strains on the conventional yokes used in the coupler assemblies presently available.
In addition, disrepair of railroad beds has caused misalignment of trackways which produces undesirable movement between adjacent railroad cars. Such movement, in turn, creates heretofore unknown fatigue failures in the components of conventional car coupling assemblies. One of the components which fails is the yoke. Thus, it has been considered desirable to provide a yoke which is stronger and more durable even under the most severe service conditions.
In order to enhance the strength of one type of coupler assembly, the components thereof have been redesigned. Such redesign is disclosed in the commonly assigned U.S. patent applications to Richard M. Hanula, Ser. No. 322,217, now U.S. Pat. No. 4,428,489, entitled ROTARY RAILROAD CAR F COUPLER, and Ser. No. 518,822, now abandoned, entitled STRIKER FOR RAILWAY CARS, the teachings of which are incorporated hereinto by reference.
Among the redesigned coupler assembly components disclosed in the above two patent applications are a connector and a striker. However, the improvements made to these components have also necessitated a new design for a yoke. One reason this has become necessary is so that the improved yoke can accommodate reinforced rear side wall portions provided on the improved striker, and so that the improved yoke can better guide the connector.
Another coupler assembly component which has been improved is the coupler itself. Such an improved coupler is disclosed in the commonly assigned U.S. patent application Ser. No. 720,798, filed on Apr. 8, 1985, to Richard M. Hanula, entitled IMPROVED COUPLER FOR RAILCAR COUPLER ASSEMBLY, the teachings of which are also incorporated hereinto by reference. The improved coupler therein mentioned has been reinforced to better withstand stresses. While providing for such reinforcement, the yoke has also required redesign to accommodate the reinforced coupler therein.
Moreover, during the coupler improvement process, it was found that the service life of the yoke was frequently reduced by premature failure at the corners of the yoke butt end due to the impact of the draft gear striking in undesirable areas. The present invention contemplates a new and improved rail car yoke which overcomes the foregoing difficulties and others, and which provides better and more advantageous overall results.